JP3128944B2 - Gear ratio control device for toroidal type continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A transmission ratio control apparatus for a toroidal type continuously variable transmission according to the present invention is used for adjusting a transmission ratio of a toroidal type continuously variable transmission used as an automobile transmission or the like.

[0002]

2. Description of the Related Art The use of a toroidal-type continuously variable transmission as schematically shown in FIG. 3 has been studied as an automobile transmission. This toroidal-type continuously variable transmission supports an input side disk 2 concentrically with an input shaft 1 and an output side disk at an end of an output shaft 3 as disclosed in, for example, Japanese Utility Model Application Laid-Open No. 62-71465. 4 is fixed. A trunnion 5, which swings around a twisted position with respect to the input shaft 1 and the output shaft 3, is provided on an inner surface of a casing containing the toroidal type continuously variable transmission or a support bracket provided in the casing. 5 are provided.

Each of the trunnions 5, 5 is made of a metal material having sufficient rigidity.
Power rollers 7 and 7 are rotatably supported around displacement shafts 6 and 6 provided at the center of the power rollers. And
The power rollers 7, 7 are sandwiched between the input side and output side disks 2, 4.

The input side and output side disks 2, 4 have one side in the axial direction facing each other, and the input side has a circular cross section centered on the swing center of each of the trunnions 5, 5. A concave surface 2a and an output-side concave surface 4a are formed. Then, the outer peripheral surfaces 7a, 7a of the power rollers 7, 7, which are formed as spherical convex surfaces, are connected to the input-side concave surface 2a and the output-side concave surface 4a.
a.

[0005] A loading device 8 of a loading cam type is provided between the input shaft 1 and the input disk 2, and the input disk 2 is elastically directed toward the output disk 4 by the pressing device 8. Is pressed. This pressurizing device 8
It comprises a cam plate 9 that rotates with the input shaft 1 and a plurality (for example, four) of rollers 11, 11 held by a holder 10. On one side surface (the right side surface in FIG. 3) of the cam plate 9, a cam surface 12 which is an uneven surface extending in the circumferential direction is formed, and the outside surface of the input side disk 2 (the left side surface in FIG. 3). Also, a similar cam surface 13 is formed. The plurality of rollers 11, 11 are rotatable about an axis in a radial direction with respect to the center of the input shaft 1.

When the cam plate 9 rotates with the rotation of the input shaft 1, a plurality of rollers 11, 11
Is pressed against the cam surface 13 on the outer surface of the input disk 2. As a result, the input side disk 2 is, at the same time is pressed against the plurality of power rollers 7 and 7, the pressing of the cam surfaces 12 and 13 and a plurality of rollers 11, 11 of the pair
The input side disk 2 rotates based on the fit . Then, the rotation of the input side disk 2 is transmitted to the output side disk 4 via the plurality of power rollers 7, 7,
The output shaft 3 fixed to the output disk 4 rotates.

When the rotational speeds of the input shaft 1 and the output shaft 3 are changed, and when the speed between the input shaft 1 and the output shaft 3 is to be reduced first, each trunnion 5 as shown in FIG. , 5 to oscillate the outer peripheral surfaces 7a, 7a of the respective power rollers 7, 7.
Are located near the center of the input side concave surface 2a and the output side concave surface 4a.
The respective displacement shafts 6, 6 are inclined so as to abut against the outer peripheral portion. Conversely, when increasing speed,
The trunnions 5, 5 are oscillated as shown in FIG. 3B so that the outer peripheral surfaces 7a, 7a of the power rollers 7, 7 are closer to the outer peripheral portion of the input side concave surface 2a and closer to the center of the output side concave surface 4a. The respective displacement shafts 6, 6 are inclined so as to abut against the respective parts. FIG. 3A shows the inclination angles of the displacement shafts 6 and 6.
2B, an intermediate speed ratio between the input shaft 1 and the output shaft 3 can be obtained.

As described above, a gear ratio control device for a toroidal-type continuously variable transmission for controlling the swing angle of each of the trunnions 5, 5 in order to change the rotational speed of the input shaft 1 and the output shaft 3 is as follows. For example, one described in JP-A-1-135958 is known.

This conventionally known gear ratio control device is:
It is configured as shown in FIG. Each of the trunnions 5,
5, pistons 14a and 14b are fixed to both ends, respectively.
A and 15b are fitted in an oil-tight manner so as to be freely displaceable and rotatable in the axial direction. And this cylinder 15
The pressure oil discharged from the pressure oil pump 16 which is a pressure oil supply device can be freely fed into a and 15b via a switching valve 17.

The switching valve 17 has a cylindrical housing 18.
And a sleeve 19 fitted inside the housing 18 so as to be displaceable in the axial direction, and a spool 20 fitted inside the sleeve 19 so as to be displaceable in the axial direction. Then, based on the relative displacement of the sleeve 19 and the spool 20 in the axial direction, one of the cylinders 15a, 15b,
15a (or 15b, 15b), pressure oil is sent to the other cylinder 15b, 15b (or 15a, 15a), and oil is discharged from the other cylinder 15b, 15b (or 15a, 15a).
The state is also switched to a state in which the supply and discharge of pressure oil are not performed.

The components 18, 1 constituting the switching valve 17
The housing 18 is fixed, and the sleeve 19 is displaced in the axial direction by an actuator 26 which is a driving device. Further, the spool 20 is displaced in the axial direction based on the rotation of the one (left side in FIG. 4) trunnion 5. That is, the base end of the piston 14b fixed to the end of the trunnion 5 is fixedly connected to the center of the piston 14b, and the distal end of the rod 21 constitutes a transmission device together with a bell crank 23 and a lever 24 described below. Precess cam 22
Is fixed.

The precess cam 22 together with the trunnion 5
Is rotated, the bell crank 2
3 swings. The proximal end of the lever 24 is connected to the end of the spool 20.
Since the compression spring 27 imparts an elastic force in a direction of coming out of the sleeve 19 (leftward direction in FIG. 4), the spool 20 is swung with the swing of the bell crank 23.
Is displaced in the axial direction of the sleeve 19.

When changing the gear ratio, the actuator 26 displaces the sleeve 19 in the axial direction according to a command from a controller (not shown). At this time, the spool 20 is still immobile. As a result, the relationship between the sleeve 19 and the spool 20 that has been in the neutral position changes until the pressure oil sent from the pressure oil pump 16 to the switching valve 17 through the oil supply pipe 28 is supplied to one of the supply oils. It is fed into one of the cylinders 15a, 15a (or 15b, 15b) through the discharge pipe 29a (or 29b).

As a result, the pistons 14a, 14a fitted to the cylinders 15a, 15a (or 15b, 15b)
a (or 14b, 14b) is pressed and each trunnion 5,
5 are displaced in the same direction with respect to the rotation direction of the disks 2, 4 (FIG. 3). At this time, the other cylinder 15
b, 15b (or 15a, 15a) presents oil
The oil is sent to the switching valve 17 through the other supply / discharge pipe 29b (or 29a), and returned to the oil reservoir 31 (see FIG. 1 showing the present invention) through the oil discharge pipe 30.

When the trunnions 5, 5 are displaced in the axial direction, the direction of the force tangentially applied to the outer peripheral surfaces of the power rollers 7, 7 pivotally supported by the trunnions 5, 5 is changed by the direction of the trunnions 5, 5. It changes relatively to the center of rotation. Based on this change, the trunnions 5 oscillate, changing the inclination angles of the power rollers 7, and changing the gear ratio between the input-side disk 2 and the output-side disk 4.

The rotation of the trunnion 5 accompanying the gear ratio conversion is
The power is transmitted to the spool 20 via the rod 21, the precess cam 22, and the lever 24, and the spool 20 is displaced in the axial direction. Cam surface 22a of the precess cam 22
The inclination direction and the inclination angle are determined in such a direction and magnitude as to cancel the relative displacement between the sleeve 19 and the spool 20 caused by the displacement of the sleeve 19 by the actuator 26. For this reason, the spool 20 is displaced in the axial direction with the rotation of the trunnion 5, whereby the switching valve 17 returns to the neutral position, and the supply and discharge of the pressure oil to and from the cylinders 15a and 15b is stopped. The power rollers 7, 7 are held in a state of being inclined at a predetermined angle.

[0017]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the size and weight of the toroidal-type continuously variable transmission gear ratio control apparatus which operates as described above and to reduce the manufacturing cost.

In the case of the conventional gear ratio control apparatus shown in FIG. 4, an actuator 26 for displacing the sleeve 19 of the switching valve 17 in the axial direction is provided independently of the switching valve 17. Inevitably, the installation space and the weight of the switching valve 17 increase.

Further, since the amount of displacement of the sleeve 19 in the axial direction had to be adjusted by the actuator 26 itself, the stroke control of the actuator 26 became troublesome, and the manufacturing cost of the actuator 26 and its control device was increased. It was inevitable that it would increase.

The gear ratio control device for a toroidal type continuously variable transmission according to the present invention has been invented in view of the above-mentioned circumstances.

[0021]

The toroidal type continuously variable transmission according to the present invention is configured as shown in FIGS. 3 and 4, for example, similarly to the above-mentioned conventional toroidal type continuously variable transmission. The rotation of the input shaft 1 is transmitted to the input side disk 2 by the action of, for example, the pressurizing device 8. One surface in the axial direction (the right side surface in FIG. 3) of the input side disk 2 is an input side concave surface 2a having an arc-shaped cross section. The output-side disk 4 having an output-side concave surface 4a having an arc-shaped cross section on one side in the axial direction (the left side surface in FIG. 3) has the output-side concave surface 4a and the input-side concave surface 2a facing each other. Rotation with respect to the input shaft 1
The input shaft 1 is supported concentrically. Each of the trunnions 5 and 5 swinging about an axis that is twisted with respect to the input shaft 1 has a base end supported by a respective one of the displacement shafts 6 and 6. The rollers 7, 7 are rotatably supported.

As shown in FIG. 4, each of the trunnions 5, 5
Pistons 14a, 14b are provided at both ends of the cylinder, and the pistons 14a, 14b are respectively connected to cylinders 15a, 15b.
Is fitted oil-tight. A switching valve 17 is provided between a pressure oil supply device such as a pressure oil pump 16 and each of the cylinders 15a and 15b. Based on the switching of the switching valve 17, the pressure oil is supplied to each of the cylinders 15a and 15b. Supply / discharge and its suspension can be performed.

As shown in FIG. 4 and FIG. 1 showing the present invention, the switching valve 17 has a sleeve 19 fitted inside a cylindrical housing 18 so as to be displaceable in the axial direction of the housing 18. Further, a spool 20 is fitted inside the sleeve 19 so as to be displaceable in the axial direction of the housing 18.

A transmission device including a precess cam 22, a bell crank 23, a lever 24 and the like is provided between any one of the plurality of trunnions 5, 5 and the spool 20. The displacement of the one trunnion 5 is transmitted to the spool 20 so that the spool 20 can be displaced in the axial direction.

Further, in the transmission ratio control apparatus for a toroidal type continuously variable transmission according to the present invention, as shown in FIG. 1, one end face of the sleeve 19 (left end face in FIG. 1) and the housing 1
A spring 32 is provided between the inner surface of one end of the housing 8 and the sleeve 19 toward the other end of the housing 18 (the right end in FIG. 1).
It is pressing elastically.

The other end (the right end in FIG. 1) of the sleeve 19 is oil-tightly closed by a lid 38. A space 33 between the other end surface of the sleeve 19 and the inner surface of the other end of the housing 18 has one end (a left end in FIG. 1) of a supply / discharge pipe 34 for supplying / discharging pressurized oil into / from the space 33. ) let through are <br/> is. A high-speed solenoid valve 37 is provided between the other end (the right end in FIG. 1) of the supply / discharge pipe 34 and the pressure oil supply pipe 35 and the oil discharge pipe 36.
Is provided. The high-speed solenoid valve 37 is connected to the supply / discharge pipe 34.
A state in which the oil supply pipe 35 is communicated with the pressure oil supply pipe 35 (upper state in FIG. 1) and a state in which the supply / drain pipe 34 and the oil drain pipe 36 are communicated (the lower state in FIG. High-speed switching is performed during a time (less than 1 second, depending on the resistance of the pipe, etc.). The pressure oil supply pipe 35 may be connected to the same pressure oil pump 16 (FIG. 4) as the oil supply pipe 28.
It may be connected to another pressure oil pump. Similarly, the oil drain pipe 36 may be connected to the oil reservoir 31 or may be connected to another oil reservoir.

As shown in FIG. 2, the high-speed solenoid valve 37
Ratio τ (= t / T) of the time t during which the supply / discharge pipe 34 and the pressure oil supply pipe 35 communicate with the predetermined short time T
By changing the pressure, the oil pressure in the space 33 is adjusted, and the axial position of the sleeve 19 in the housing 18 is adjusted.

That is, as shown in FIG. 2 (A), if the time t ₁ during which the supply / discharge pipe 34 and the pressure oil supply pipe 35 communicate with each other and the ratio τ is reduced, the space As the pressure in 33 decreases, the sleeve 19 is pushed by the spring 32 and displaced inside the housing 18 toward the other end (the right side in FIG. 1). Conversely, as shown in FIG. 2 (B), and the supply and discharge line 34 and the hydraulic fluid supply pipe 35 to increase the time t ₂ in communication, by increasing the ratio tau, in the space 33 Is increased, the sleeve 19 pushes the spring 32, and is displaced to one end (left side in FIG. 1) inside the housing 18.

[0029]

The input shaft 1 and the output shaft 3 are provided by the transmission ratio control apparatus for a toroidal-type continuously variable transmission according to the present invention having the above-described structure.
To change the gear ratio freely between
The operation itself when changing the inclination angle of 5 is the same as in the case of the above-described conventional toroidal type continuously variable transmission gear ratio control device.

In particular, in the case of the transmission ratio control device for a toroidal type continuously variable transmission according to the present invention, one end of a sleeve 19 fitted inside the housing 18 is closed, and this sleeve 19 is directly pushed by hydraulic pressure. Since the axial position of the sleeve 19 is adjusted by balancing with the spring 32, the size and weight of the switching valve 17 and the control device of the switching valve 17 can be reduced.

Although the hydraulic pressure in the space 33 is controlled by adjusting the switching time of the high-speed solenoid valve 37, the switching time can be adjusted by simple electric control.
Further, based on the switching of the high-speed solenoid valve 37, the empty
By finely switching the hydraulic pressure introduction into the space 33,
The switching valve 17 vibrates finely.
The power is transmitted to the bell crank 23 and the precess cam 22. this
Therefore, the friction of the engaging portion between these members 24, 23, 22
The state changes from static friction to dynamic friction,
Between the set cam 22 and the spool 20 of the switching valve 17
Displacement transmission can be performed smoothly. As a result, these precesses
Reduce the hysteresis between cam 22 and spool 20
As a result, smooth and precise gear ratio control can be performed.

[0032]

The gear ratio control apparatus for a toroidal type continuously variable transmission according to the present invention is constructed and operates as described above.
The size and weight can be reduced and the manufacturing cost can be reduced. Also, smoothly and
Performs precise gear ratio control to produce a toroidal-type continuously variable transmission
Performance can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a transmission ratio control device for a toroidal type continuously variable transmission according to the present invention.

FIG. 2 is a diagram showing a switching state of a high-speed solenoid valve.

FIG. 3 is a side view showing the basic structure of the toroidal-type continuously variable transmission in a state of maximum deceleration and a state of maximum acceleration.

FIG. 4 is a sectional view of a conventional gear ratio control device for a toroidal-type continuously variable transmission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input shaft 2 Input side disk 2a Input side concave surface 3 Output shaft 4 Output side disk 4a Output side concave surface 5 Trunnion 6 Displacement axis 7 Power roller 7a Outer peripheral surface 8 Pressurizing device 9 Cam plate 10 Cage 11 Roller 12 Cam surface 13 Cam Surface 14a, 14b Piston 15a, 15b Cylinder 16 Pressure oil pump 17 Switching valve 18 Housing 19 Sleeve 20 Spool 21 Rod 22 Precess cam 22a Cam surface 23 Bell crank 24 Lever 25 Shaft 26 Actuator 27 Compression spring 28 Oil supply pipe 29a, 29b Supply / discharge pipe Reference Signs List 30 oil drain pipe 31 oil reservoir 32 spring 33 space 34 supply / drain pipe 35 pressure oil supply pipe 36 oil drain pipe 37 high-speed solenoid valve 38 lid

Claims (1)

(57) [Claims] An input shaft, an input side disc having an arcuate cross section on one side in the axial direction, an input disk rotating with the rotation of the input shaft, and an output section having an arcuate cross section on one side in the axial direction. A side concave surface, in a state where the output side concave surface and the input side concave surface face each other, and freely rotate with respect to the input shaft,
An output-side disk supported concentrically with the input shaft, a plurality of trunnions swinging at a twisted position with respect to the input shaft, and a displacement shaft having a base end supported and fixed to each trunnion,
An annular power roller which is rotatably supported by each displacement shaft and has an outer peripheral surface having a spherical convex surface abutting on the input side concave surface and the output side concave surface, and each of the trunnions in the respective axial direction.
In order to displace, it is provided at the end of each of these trunnions
A piston, a plurality of cylinders each of which is fitted oil-tightly with a piston, a pressure oil supply device, and a spool inside a sleeve which is fitted inside the cylindrical housing so as to be displaceable in the axial direction of the housing. Is disposed between the pressurized oil supply device and the plurality of cylinders so as to be capable of being displaced in the axial direction. A switching valve for controlling a stop, a transmission device for transmitting a displacement of any one of the plurality of trunnions to the spool, and displacing the spool in the axial direction; In a transmission ratio control device for a toroidal-type continuously variable transmission having a driving device for displacing the sleeve, the sleeve is provided between one end surface of the sleeve and an inner surface of one end portion of the housing. A spring that elastically presses toward the other end of the sleeve is provided, the other end of the sleeve is oil-tightly closed, and the other end of the sleeve and the inner surface of the other end of the housing are connected to each other. One end of a supply / discharge pipe for supplying / discharging the pressure oil to / from this space communicates with the space between them, and the space between the other end of the supply / discharge pipe and the pressure oil supply pipe / drain pipe is A high-speed solenoid valve is provided for switching between a state in which the supply / discharge pipe communicates with the pressure oil supply pipe and a state in which the supply / discharge pipe communicates with the oil discharge pipe at a high speed in a predetermined short time. for a short period of time, by said supply and discharge line and the hydraulic fluid supply pipe varying the proportion of time in communication, by adjusting the pressure in said space, this
A gear ratio control device for a toroidal-type continuously variable transmission, wherein an axial position of the sleeve in the housing, which is determined by a balance between a hydraulic pressure and an elasticity of the spring, is adjusted.